In a study published this year, researchers looked exclusively at heterosexual women's preferences for attractiveness and altruism in men.

About 200 women were asked to look at photographs of men's faces. Half those faces had been determined to be extremely physically attractive; the other half had been determined to be extremely physically unattractive.

The women saw two pairs of faces at a time, one attractive and one unattractive.

Each pair of faces was displayed alongside a description of a scenario and how each man behaved. For example: "two people are walking through a busy town and see a homeless person sitting near a cafe." One man goes into the cafe and buys a sandwich and tea for the homeless person; the other man pretends to use his cellphone and walks straight past the homeless person.

All the women were asked to rate each man on how attractive he was for a short- or long-term relationship.

The researchers walked away with several key findings.

First, as previous research had found, altruistic men were more attractive than nonaltruistic men.

Second, altruistic men were more attractive for long-term than short-term relationships. When it came to short-term relationships, nonaltruistic men were in fact more desirable than altruistic men.

Perhaps the most striking finding was that altruism appeared to be even more appealing than physical attractiveness when it came to long-term relationships. Unattractive men high in altruism were rated more attractive for long-term relationships than attractive men low in altruism.

It's hard to say whether these study findings apply to real-life interactions. But they do suggest that, if you're a man looking for a committed relationship with a woman, you shouldn't hesitate to flaunt the fact that you're an unpaid mentor for elementary-school kids or that you help your elderly neighbor buy groceries every week.

It could be an easy way to gain an edge over the more self-oriented guys out there.